Food and Nutritional Sciences - Masters by Research Theses

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A comparison of the use of whole milk and fat-filled milk powders for production of heat-stable long-life beverages
(University College Cork, 2020-04) Crotty, Aisling; Kelly, Alan; O'Mahony, Seamus Anthony; Enterprise Ireland; Dairy Processing Technology Centre
Commercial bovine milk is 3.5% fat, the level of which is affected by seasonality, stage of lactation, feed, health, breed, and even the individual teat. Milk (and other liquid dairy products) are highly perishable due to their nutritional quality, as they are the sole source of nutrition for the neonate. As a result, milk is often dehydrated into powder form, which enhances its shelf life, its storage stability, and the convenience. Another way to enhance the shelf life of milk is to subject it to heat to destroy pathogenic bacteria, enzymes, spores, and to enhance the shelf life of the product. As most dairy products are subjected to some form of heat treatment, their heat stability is integral to the overall quality of the product. In Chapter 2, two reconstituted dairy powders (fat-filled milk powder (FFMP) and whole milk powder (WMP)) were compared under two heat treatments (UHT-processing and retort sterilisation), and three protein contents (2.3, 3.3, and 5%). These variables significantly affected the apparent viscosity, the pH, the colour, the emulsion stability, and the average particle size of the samples. Chapter 3 investigated the influence of calcium-chelating salts on heat stability. These salts are an often-used ingredient in dairy products, as they enhance the heat stability of the system by binding the calcium ions, which are important for casein micelle integrity. The influence of trisodium citrate (TSC), disodium hydrogen phosphate (DSHP), and sodium hexametaphosphate (SHMP) on heat stability, colour, and apparent viscosity was examined. SHMP had the most significant effect on heat stability, colour, and apparent viscosity due to its chelating capacity and its influence on cross-linking between the casein micelles. DSHP had no significant effect on viscosity or colour, whereas the addition of 20 mmol/L of TSC significantly affected the colour of the solution.
Compositional and analytical factors affecting the stickiness of dairy powders
(University College Cork, 2019-10) O'Donoghue, Laura T.; O'Mahony, Seamus Anthony; Murphy, Eoin; Enterprise Ireland
Spray dying is a dehydration technique used in the dairy industry for the preservation and creation of a wide range of valuable dairy products. However, challenges associated with stickiness development are often encountered during spray drying, particularly with spray dryer feed streams containing high levels of lactose, which can lead to lower yields, reduced powder quality and shorter runs. Stickiness in lactose-containing powders is related to the glass transition phenomenon, in which a phase change occurs in the amorphous form of lactose, causing a decrease in the viscosity of the powder particle surface, leading to liquid bridging and ultimately stickiness between particles and/or to equipment surfaces. There is a wide variety of compositional and environmental factors that affect the rate and extent of stickiness development in dairy powders, such as the temperature and relative humidity of the air or the protein content of the powder. The first objective of this study was to investigate the influence of particle size on the physicochemical properties and stickiness behaviour of a selection of lactose-containing dairy powders. Using a fluidisation technique, this work demonstrated that stickiness increased with decreasing particle size for lactose-containing dairy powders. Stickiness may be characterised using a number of different instrumental approaches, which can be categorised as direct/indirect or static/dynamic techniques. However, most methods provide a binary definition of stickiness (i.e., sticky or non-sticky), which while pragmatic, does not provide information regarding the mechanical relaxations which contribute to stickiness. Therefore, the second objective of this study was to examine the use of dynamic mechanical analysis (DMA) to characterise temperature- and humidity-induced relaxation behaviour of whey protein concentrate (WPC) powders; results were also compared to two other established techniques, differential scanning calorimetry (DSC) and a fluidisation method. The results demonstrated that while DMA may not be an accurate method for stickiness determination, it could prove useful as a complementary method when combined with stickiness techniques (e.g., fluidisation) to provide more detailed information on the physical changes occurring during stickiness. Overall, the findings of this research will prove useful to dairy processors at minimising issues with stickiness during drying and may also potentially provide powder technologists with a new method for tracking the physical transitions that occur during stickiness development of dairy powders.
Development of patient resources for oncology patients with dysphagia and disease-related malnutrition
(University College Cork, 2021-12-21) Hanna, Michelle; Ryan, Aoife; Power, Derek; Breakthrough Cancer Research; Oesophageal Cancer Fund
Cancer is a leading cause of both morbidity and mortality globally [1]. Additionally, its incidence is continuing to rise year on year. Thus the development of treatments and supports to tackle and reduce cancer morbidity and mortality is of crucial importance. Current research highlights that the loss of body weight, and significantly lean body mass, contributes to increased risk of mortality in those with cancer [2, 3]. Cancer itself and its treatments can cause a variety of debilitating side-effects. These can in turn affect a person’s appetite and their ability to chew and swallow normally. Those suffering from cancers of the head and neck and upper gastrointestinal tract are particularly susceptible to dysphagia (difficulty swallowing), often related to the location of the tumour and its treatment [4]. These negative effects on appetite and normal eating lead to reduced food intake and quality of life, significant weight loss and malnutrition. A supportive, multifaceted, evidence-based approach from an early stage is required to attenuate the development of malnutrition and thus minimise its detrimental impact on treatment outcomes and quality of life. Involuntary weight loss affects between 50-80% of those with cancer and is associated with reduced quality of life, psychological implications, increased treatment-related complications and poorer survival [5]. Currently, no known cure exists for cancer-induced weight loss. The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines for cancer patients recommend nutrition counselling as the first line of nutrition therapy, and state that the best way to increase energy and protein intake is with normal food: a food-first approach [6]. Prior to the publication of ‘Good Nutrition for Cancer Recovery’ by University College Cork in 2014 no evidence-based resource existed that provided patients with understandable and reliable nutritional information and nourishing recipes to help attenuate cancer-induced weight loss through a food-first approach. A 130-page, evidence-based resource containing 52 high protein, high calorie recipes was created but has been out of print since 2018. To address this, as part of this thesis, a second expanded edition was created: a 250+ page resource containing information, advice, and a bank of 116 nourishing recipes. This is described in chapter 2. All recipes are fortified with high-protein, high-calorie additions and portion sizes were adjusted to ensure meals were small in volume for those with a reduced appetite. The revision of the original recipes also allowed for an enhanced protein to fat ratio and all recipes comply with the energy and protein goals set by the British Dietetic Association (BDA) for nutritionally vulnerable patients [7]. Patients with solid tumours of their upper gastrointestinal tract are especially vulnerable to cancer-induced weight loss, exacerbated by dysphagia [4]. Difficulty chewing and swallowing reduce dietary intake and puts this population at an increased risk of malnutrition. In 2016, a novel written resource, ‘Eating Well with Swallowing Difficulties in Cancer’ was developed by University College Cork, aiming to help attenuate malnutrition and sarcopenia in cancer patients experiencing dysphagia. It consisted of 59 nourishing, texture-modified recipes and evidence-based nutrition advice and information based on the ‘Irish Consistency Descriptors for Modified Fluids and Food (2009)’ [APPENDIX 4]. Ireland’s changeover in 2019 to the International Dysphagia Diet Standardisation Initiative (IDDSI) led to changes in framework structure, terminology used and testing methods, thus all dysphagia resources required updating for compliance. IDDSI is a global initiative providing universal terminology describing food texture and fluid thickness, as used in dysphagia diets [8]. Chapter 3 of this thesis discusses the development of the written resources aimed to help optimise oral intake and attenuate weight loss in head and neck and upper gastrointestinal cancer patients experiencing dysphagia, according to the IDDSI framework. It outlines the creation of appealing recipes that are nourishing and texture-modified for IDDSI levels 3 and 4. These resources aim to help those with cancer in achieving nutrition requirements with all recipes developed to comply fully with the appropriate IDDSI level. It is hoped that these cookbooks with help both patients and their families cope with the challenges of a texture- modified diet and that they will become a useful resource for dietitians and other health care professionals in providing advice on IDDSI meals. Recipes were fortified with high protein, high calorie additions; portion sizes were adjusted to low-volume for easier eating, and texture was altered to meet modified texture guidelines. Thousands of copies of these resource will be printed and distributed to oncology centres nationwide in order to disseminate this knowledge, free of charge, to cancer patients. Chapter 4 of this thesis describes the development of an evidence-based cancer information and support website. With so much unfiltered information available, there is often a lot of confusion around what to believe in relation to diet and cancer. This can leave people extremely vulnerable to misleading information at what is already a very difficult time in their lives. To address this, a one-stop-shop evidence-based website was created. The aim of this website was to dispel the most common myths and misinformation on diet and cancer and provide simplified evidence-based information for people throughout their cancer journey. The main sections covered included problems which may affect eating, cancer prevention, cancer survivors, dysphagia and cancer myths and misconceptions. The overall conclusions are summarised in Chapter 5. Malnutrition is a condition with a multifactorial aetiology and thus must be treated with an effective multimodal approach. However, this is outside the scope of this thesis which deals with its nutritional aspect. Dietary intake may be optimised by providing patients with a resource of high-calorie high-protein, nourishing recipes to improve oral intake and, potentially, attenuate loss of weight and muscle mass – such as the cookbook ‘Good Nutrition for Cancer Recovery’. For those with cancer experiencing swallowing difficulties in addition to malnutrition, separate resources with specific tailored advice, based on IDDSI guidelines, were published. Prior to these booklets being published, no resource existed to tackle the challenging task of creating high protein high calorie recipes which were also texture-modified according to the IDDSI guidelines. To support both projects and patients throughout their cancer journeys, a comprehensive website with easily accessible evidence-based information was created.
The effects of bioavailable dairy whey peptides on nerve and muscle health
(University College Cork, 2021-04-26) Gilmartin, Sarah; O'Brien, Nora M.; Giblin, Linda; Teagasc
As we age, we lose skeletal muscle mass and strength. Muscle ageing can be reversed or delayed by a combination of exercise and dietary protein. There is an increasing amount of evidence from intervention trials that consumption of whey has positive benefits on ageing muscle health. Bovine whey proteins (β-Lactoglobulin (β-Lac), α-Lactalbumin (α-Lac), Bovine Serum Albumin (BSA) and Lactoferrin) are high quality dairy proteins that are easily digested contain all essential amino acids and are rich in branched chain amino acids. These proteins are also noted for their bioactive peptides. This thesis examines the effects of up to 5 bioavailable whey peptides, TKIPA (β-Lac), NLPPL (BSA), KVPQ (BSA), VAGT (β-Lac) and VGIN (α-Lac) on redox and inflammatory biomarkers in muscle and microglial cell lines. All five peptides significantly protected C2C12 cells from free radical damage with two peptides NLPPL and VAGT having positive effects in both C2C12 and BV-2 cells. In addition, this study reports on the levels of 3 inflammatory biomarkers of ageing (Interleukin 1-β, Interleukin- 6 and Tumour Necrosis Factor alpha) in a limited number of frail older adults in Ireland. The preliminary results from the bloods indicate that IL-6, IL-1, TNF- are elevated in the older Irish frail population.
The glycaemic index of fresh and processed potatoes
(University College Cork, 2020-10-16) Muldoon, Aine; O'Brien, Nora M.; O'Connor, Thomas P.; Department of Agriculture, Food and the Marine, Ireland
Potatoes are an important staple food, which provide vital nutrition to millions of people globally every year. However, potatoes have a relatively high carbohydrate content as well as being generally considered as a high Glycaemic Index (GI) food. Research suggests that the consumption of potatoes or high GI foods can contribute to the onset of certain chronic conditions such as cardiovascular disease and type II diabetes. The supposed link between potatoes and negative health outcomes has led to a decline in their consumption in the developed world. The aim of this thesis was to assess the GI, glycaemic load (GL), and carbohydrate parameters of selected potato cultivars using an in-vitro method. The main objectives of the research were to employ various interventions in an attempt to reduce the GI and GL of the potatoes. Five potato cultivars commonly consumed in Ireland (Cultra, Gemson, Kerr’s Pink, Maris Piper, and Rooster) were tested. All varieties were found to have a medium or high GI. Evidence suggests that certain types of processing can reduce GI therefore each of the potato cultivars were then subjected to high pressure processing (HPP) at either 400Mpa or 600Mpa. In the potatoes which had the highest GI a decline in the GI was observed as the pressure was increased, however this decrease in GI was not seen in the potato varieties with a lower GI. Roosters were selected for further testing as they are the most widely produced and consumed potato variety in Ireland. To determine the effect of added fat on GI, a dose response was conducted by adding 10%, 15%, 20% or 25% (w/w) of rapeseed oil to potato and measuring GI. The GI of potato was also assessed following addition of butter, coconut oil, or olive oil at a concentration of 10% (w/w). No significant changes in GI or GL of the potato were observed following the addition of fat at any concentration; nor did the degree of saturation of the added fat impact GI or GL. The impact of combining Roosters with either cheese, peas, beans, or tuna on the GI of the resultant meal was investigated. Each meal consisted of 50g of available carbohydrates. Roosters alone had a medium GL, this was reduced to a low GL when they were included as part of a meal. The GI was also reduced for every meal in comparison to Rooster alone, apart from the potato-tuna meal. The greatest decrease in the GI was observed when Rooster were combined with beans which are a rich source of fibre. Consequently, the addition of three fibres; pectin, HPMC (hydroxypropylmethylcellulose), or inulin was investigated as a means of reducing the GI of Rooster potatoes. The fibres were tested at three concentrations 5%, 7% or 10% (w/w). The viscosity of the digesta as well as the carbohydrate parameters were measured. Pectin induced the greatest reduction to the GI out of all three fibres, whilst causing the highest increase in viscosity. HPMC had a similar but less pronounced effect, whilst inulin did not affect the GI. Finally, the impact of HPMC on carbohydrate parameters in sweet potatoes as well as the antioxidant potential of both Roosters and sweet potatoes was investigated. Ferric reducing antioxidant potential (FRAP), Oxygen radical absorbance capacity (ORAC), total phenol content (TPC), as well as ascorbic acid content were quantified. The addition of the fibre caused reductions in the FRAP and ascorbic acid content of the tubers however, ORAC and TPC values remained unchanged. Overall, our findings have identified methods to potentially reduce the GI of potatoes which could be useful for the food industry and have also demonstrated that in-vitro methods can be a convenient tool for the determination of GI and GL in potato and potato-based meals.
Mechanical integrity and rehydration properties of agglomerated nutritional dairy ingredient powders
(University College Cork, 2019-12-22) Hazlett, Ryan; O'Mahony, Seamus Anthony
The functional properties of nutritional dairy powders are key in determining the ease at which they can be stored, handled and further applied in formulations or on direct consumer application. Powder agglomeration is a unit operation employed during the spray drying process, in order to obtain a greater control of the resulting powder’s physical, bulk handling and functional properties. The studies presented in this thesis explore the importance of maintaining agglomerate integrity on powder handling (i.e., powder conveying) post-spray drying, while presenting novel research findings in the application of agglomeration for the modification of commercially important, high-protein content dairy powders (e.g., milk protein isolate; MPI). Initially, a custom fabricated pressure dispersion rig was utilised to achieve breakdown of agglomerated powder particles, similar to that occurring in industrial powder conveying systems (i.e., lean phase conveying). Analysis of the resulting powders showed that the significant alterations in both powder physical and bulk properties (i.e., decreased particle size, increased bulk density and increased surface free fat concentrations), occurring on agglomerate breakdown, significantly impaired the functionality (i.e., flowability and rehydration) of a range of commercially agglomerated nutritional dairy powders (i.e., whey protein concentrate, fat-filled milk powder and an infant formula powder). In addition, the agglomeration of MPI was researched, focusing on the utilisation of novel protein-based binders to achieve agglomeration. The results demonstrated that the use of novel protein-based binder solutions achieved a greater extent of agglomeration in comparison to more traditional binder solutions (i.e., water or lactose), ultimately improving the flowability and wetting properties of MPI powders. The conclusions of this thesis demonstrate the importance of maintaining the mechanical integrity of agglomerated dairy powders and the potential for the further application of agglomeration using novel protein-based binder solutions to tailor the functionality of high-protein dairy powders, such as MPI.
Novel, clean label sweetening ingredients in reduced sucrose cake and biscuits
(University College Cork, 2020) Milner, Laura; O'Sullivan, Maurice; Kerry, Joseph; Department of Agriculture, Food and the Marine Ireland
High levels of sucrose in food has been linked with an increase risk of developing obesity and type 2 diabetes. Therefore a reduced sugar intake is strongly recommended by health professionals. Sweet baked products contain high levels of sucrose. Sucrose was reduced by 30% in cake and biscuit formulations and a variety of potential sweetening alternatives were studied. The fundamental rheology of the control and reformulated raw cake batters and biscuit doughs were recorded. The microstructure of the batters and doughs were captured using light microscopy (LM), confocal laser scanning microscopy (CLSM) and cryo-scanning electron microscopy (cryo-SEM). At high frequencies (10Hz), batter containing polydextrose and apple pomace had a significantly greater complex modulus (G*), indicating a firmer batter. There was no significant change to the rheological properties of the biscuit doughs. LM revealed a reduction in sucrose yielded a batter with increased bubble size. Reformulated biscuit doughs remained similar to the control dough as seen by the LM. CLSM and cryo- SEM showed the reformulated batters and doughs were similar to the control however there was an increase in the cellulosic material in batters and dough containing fibrous material. The batters and doughs were baked and the resulting products’ properties were examined. The physical characteristics, texture profile, staling properties and microstructure of the reformulated cakes were examined. Sensory evaluation was also conducted. Oligofructose, whey permeate and polydextrose-containing cakes had similar characteristics to the control with regard to specific volume, colour, and texture. The addition of apple pomace resulted in cake with a decreased specific volume, harder crumb and a darker crumb and crust which received the lowest scores of the reformulated cakes in many attributes as ranked by the sensory panellists. The C-Cell revealed the 2D crumb structure did not significantly change. However CLSM revealed cakes containing apple pomace had an increase in cellulosic material. The reformulated cakes had a total sugar reduction of between 21.5-27.6%. A biscuit formulation was reduced by 30% sucrose and a combination of bulking agents (polydextrose, maltodextrin, plant fibres) with extracts (yeast, apple) and natural flavourings were investigated as sucrose replacers. When compared to the control biscuits, the addition of citrus fibres and apple extract (CFA) resulted in biscuits with an increased hardness, moisture content and water activity and a decreased lightness (L* value) and overall acceptability (as evaluated by the sensory panellists). Overall, biscuits containing cereal fibres and a natural flavouring received high sensory scores for colour, appearance, sweetness, aftertaste and overall acceptability. The polydextrose and a natural flavouring-containing biscuits achieved high scores for flavour, sweetness, aftertaste and overall acceptability compared to the control (over 5.5 on the hedonic scale). A total sucrose reduction of 14.7-28.6% was achieved compared to the control formulation. The volatile profile, staling and sound (acoustic) properties of reduced sucrose biscuits enriched with citrus fibre and polydextrose were evaluated. There was a significant increase in the moisture content, water activity and fracturability in the reformulated biscuits and a significant decrease in the acoustic emissions and sensory scores as evaluated by the panellists. This indicates the high moisture content, water activity and fracturability negatively influenced the acoustic properties of the reformulated biscuits. Volatile profile analysis revealed a decrease in Maillard reaction-derived compounds and an increase in lipid oxidation-derived compounds. Sensory evaluation deemed the biscuits as acceptable.
Nutrient intakes, compliance with recommendations and key sources in women of child-bearing age (18-50y) in Ireland
(University College Cork, 2022-02-09) O'Mahony, Abigail; Walton, Janette; Kehoe, Laura; Flynn, Albert; Cashman, Kevin; Coffey, Aidan
Background: Women’s pre-conceptional health (including nutritional status) is important for both the health of the individual themselves and also for the lifelong health of any occurring offspring. However, it has been estimated that up to 50% of pregnancies are unplanned, thus optimal nutritional status is important for all women of child-bearing age (WCBA) not just those with pregnancy intentions. Despite the accumulation of evidence of the importance of nutritional status at this life-stage, nutrient recommendations for WCBA for the most part don’t differ from recommendations for other population groups. The notable exception to this is that all WCBA are recommended to take a folic acid supplement to reduce the risk of neural tube defects (NTDs) in an occurring pregnancy. Objectives: The overall aim of this thesis was to estimate the nutrient intakes among WCBA in Ireland. The first aim was to estimate the mean daily intake of energy, macronutrients, dietary fibre and salt, to determine compliance with dietary guidelines and to identify the key dietary sources of these nutrients in WCBA. A further aim was to estimate the mean daily intake of micronutrients, the prevalence of inadequate intakes and risk of excessive intakes and to identify the key dietary sources of micronutrient intakes in this population group. Methods: The analysis for this research was based on data from the subset of WCBA (18-50 years) (n 487) in the Irish National Adult Nutrition Survey (NANS) (2008-2010). Food and beverage intakes were estimated using a 4-day semi-weighed food record. Nutrient intakes were estimated using WISP® which uses data from ‘McCance and Widdowson’s the Composition of Foods’, Sixth Edition (plus all nine supplemental volumes). During the NANS, modifications were made to the food composition database to include recipes of composite dishes, fortified foods, nutritional supplements, generic Irish foods that were commonly consumed and new foods on the market. The mean daily intake (MDI) of energy and nutrients were estimated by summing the total amount of energy and each nutrient consumed and dividing the total by the number of recording days (four) using SPSS® Version 26. Compliance with dietary guidelines was examined for macronutrients, dietary fibre and salt. The prevalence of inadequate micronutrient intakes (% upper levels (UL)) was also determined. The percent contribution of specific food groups to mean daily intakes of energy, macro- and micro-nutrients was calculated by the mean proportion method. Results: This study found that that while protein intakes are sufficient among WCBA in Ireland, a large proportion of this population have total fat intakes above recommendations (42%) and carbohydrate intakes below recommendations (59%). This population group also have high intakes of saturated fat (13% of total energy (%TE)), free sugar (9%TE) and salt (5.5g/d from food sources only) and low intakes of dietary fibre (17g/d). Important sources of energy in the diet were ‘cereal & cereal products’ (including potatoes) ‘meat, fish & eggs’ and ‘dairy & dairy products’ which when combined contributed over two-thirds of energy intake on average. However ‘top-shelf’ foods (i.e. ‘sugars, confectionery, preserves & savoury snacks’, ‘biscuits, cakes & pastries’ and ‘sugar-sweetened beverages’) also contributed a high proportion of energy intake (21%) in addition to contributing significantly to intakes of fat (15%), saturated fat (16%) and free sugars (59%). This population group also have high intakes of saturated fat (13% of total energy (%TE)), free sugar (9%TE) and salt (5.5g/d from food sources only) and low intakes of dietary fibre (17g/d). With regard to micronutrients, significant proportions of WCBA have inadequate intakes of vitamin D (93%), vitamin C (48%), calcium (41%), folate (32%), iodine (26%), riboflavin (25%), vitamin A (18%), magnesium (18%) and iron (10%). There was little risk of excessive intakes of micronutrients among WCBA with negligible proportions (<3%) of this population having intakes of vitamin B6 and iron greater than the UL. Important sources of vitamins and minerals were milk and milk products, meats, breads and cereals, especially fortified breakfast cereals, and fruits and vegetables. Conclusions: In summary, this study has found unfavourable intakes of total and saturated fat, carbohydrate, sugar, salt and dietary fibre together with low intakes of key micronutrients in WCBA in Ireland. The data presented in this study will have important implications for public health guidance for this vulnerable population group. Furthermore, information about the relative contributions of specific foods to nutrient intakes will be useful to both policy makers and the food industry to develop targeted dietary strategies to improve the diets of WCBA in Ireland.
The optimization of plant protein meat re-placers and clean label water binders in processed meat (white pudding and chicken)
(University College Cork, 2021-10-31) Garvey O'Driscoll, Seán; O'Sullivan, Maurice; Kerry, Joseph; Ryan, Sinéad
Reformulations and the development of bespoke vegetarian/vegan products, are becoming increasingly popular for a host of reasons, including health, environmental, economic and ethical concerns. Processed meat products have been under the spotlight for much of the recent past, with particular regard to their typically higher fat and salt contents and the health consequences of these, as well as the impact of meat production on the environment. Therefore, the interest in plant-based alternatives is continuing to grow. A sequential reduction of meat and animal fat with either chickpea or red lentil protein was performed in white pudding, with the overall goal of producing an acceptable 100% vegan product, or failing this, identifying the optimal replacement level that was acceptable to consumers and would not compromise on technological quality. The technological, compositional and sensory quality of the samples were analysed. Replacement was performed in 10% increments from 10% to 100%. Samples that contained more chickpea or red lentil protein than meat and animal fat (50% + replacement) were significantly (P<0.05) less acceptable from a sensory perspective, while they were also significantly (P<0.05) higher in protein content, lower fat content and lower in pH. Overall, a vegan sample was not a viable possibility under the parameters due to significant deterioration in sensory and technological quality and the optimum replacement level was identified at 20% for both proteins. Replacement was possible up to 40% for CP and 30% for RLP before quality started to deteriorate. Further optimisation of the formula and/or production method to achieve further replacement of the meat and animal fat. Recent years have seen an increase in demand for products that are perceived to be more “natural”, organic, containing less additives and preservatives or by utilising clean label ingredients. Phosphates, a common water binding agent, are one such food ingredient that consumers may actively seek to avoid. Sodium triphosphate (STPP) was sequentially replaced (25%, 50%, 75%, 100%) with Aquamin soluble, citrus fibre and carrageenan in a brine intended for injection into chicken breast fillets. The effect of the replacement on the technological, sensory and microbiological quality of the cooked chicken (in the form of restructured chicken hams) was investigated. The overall objective was to produce a phosphate-free brine system utilising Aquamin soluble as well as any other ingredients deemed necessary. Replacement yielded significantly (P<0.05) more acidic brines and cooked samples alongside a significant increase in WHC. The sensory quality was unaffected by replacement, with no significant differences in overall acceptability between samples. Similarly, no significant improvements or deterioration in microbiological quality were identified, though the acidic nature of the 75% and 100% replacement samples may have had a slight statistically nonsignificant antibacterial effect. Ultimately, the complete replacement of STPP yielded a cooked chicken sample that performed largely on par with one or two exceptions, most notably cook yield, in the quality parameters to the control. Further optimisation could be performed to address cook yield and protein solubilisation of the 100% replacement sample, as well as to attempt to produce a completely clean label brine, as carrageenan is not considered a clean label ingredient.
Temporal sensory liking methods: an investigation with beef steaks from different production systems
(University College Cork, 2022) Corcoran, Linda; O'Sullivan, Maurice; Crofton, Emily; Teagasc
Research on the impact of the diet of the animal on consumer liking of beef has yielded conflicting results. The aim of this study was to apply the traditional liking method and two temporal liking (TL) methods (free and structured) to determine consumer liking of beef derived from animals that were fed grain (GF), grass silage and grain (SG) or grazed grass (GG) during finishing and use different methods to determine the data quality and consumers variability. Three separate panels of regular beef-eating consumers (n=51; n=52; n=50) were recruited from students and staff at Teagasc Food Research Centre, Dublin, Ireland, to assess the liking of striploin steaks from animals fed either GF, SG, or GG, respectively. Results of chapter 2 revealed significant differences (p≤0.05) in liking between diets in terms of overall liking, juiciness, and tenderness using the free TL method. These effects were not observed using the structured TL or traditional liking methods. Further statistical analysis of the TL methods found that the free TL method yielded more discriminative data than the structured TL method, with significant differences (p≤0.05) found for both overall liking and juiciness. Consumers also found the free TL method easier to perform compared to the structured TL method. The evolution of scores over time (changes in consumer scores over the scoring period) was significant (p≤0.05) for all attributes using the free TL method. These results show that free TL may give rise to new opportunities to elicit more in-depth insight from consumer studies using meat. In addition to answering the research question, TL data also has the potential to give new insight into consumer behaviour in terms of how people approach temporal 8 sensory liking methods. Chapter 3 utilises this consumer behaviour approach to look at three temporal liking studies applying both structured and free TL in terms of data quality, presence or absence of temporality, and correlations between consumer response and self-reported difficulty. Interestingly, the assessment of temporality found that consumers who showed the ability to provide temporal data did not provide it for all attributes studied. The analyses have also demonstrated areas where fatigue and the natural variability in consumer responses may impact data quality. Chapter 4 further analyses data from study 2 from chapters 2 and 3 as this had no missing data. Studies 1 and 3 had missing data due to consumers not providing responses to all time points and attributes during sensory testing. Two TL methods (free and structured) and a traditional liking method were employed to generate data from consumers on their liking of beef steaks derived from a grain supplementation diet for four attributes (overall liking, flavour, tenderness, juiciness). Consumers spent the most time and gave the most responses to the attribute flavour. High levels of variability were found within each liking method. High correlations were also found between attributes within each liking method. For the structured TL, overall liking was found to be significant over time. In addition, the free TL and traditional liking were found to be significantly different from each other (p≤0.05) for liking and flavour attributes and the structured TL and traditional liking were found to be significantly different from each other for flavour. However, the two temporal liking methods did not differ from each other. Two clusters of consumers were found for each attribute, one who slightly liked the attribute and one who slightly disliked the attribute. Some consumers changed cluster groups between attributes. This study has shown that the choice of TL method may make a difference on the data elicited.
Tribology of malt-based beverages: development and application of method
(University College Cork, 2021) Fox, Daniel; Arendt, Elke K.; Fonds Baillet Latour
Soft tribology, i.e. the measurement of friction as a function of speed between two compliant surfaces, has found applications in food science and there is a growing body of theoretical and practical knowledge of fundamental mechanisms of lubrication as well as increasingly strong correlations between tribology and sensory data. Soft tribology is generally conducted using either commercially or in-house built tribometers however, the recent decade has seen a rise in the use of rheometers with tribology attachments. Based on current literature, knowledge gaps and potential avenues for future research have been identified. These include investigations on hydrophobicity of surfaces, surface wear (running-in), cleaning procedure of the attachment and tribopairs, speed (range and method of increase/decrease) and measuring system configuration. In the current research, frictional parameters of 10 beers (5 alcoholic and their non-alcoholic counterpart) were measured using an Anton Paar MCR301 rheometer with a tribology attachment (BC12.7, Anton Paar, Graz, Austria), and a range of variables was extracted and subjected to dimension reduction analysis (Principal Component Analysis, clustering, and correlation analysis). Sensory data consisting of a numeric mouthfeel rating and written reviews from an online beer-rating website (www.ratebeer.com) were compiled, transformed, and correlated with the tribology data. Based on Frictional parameters of the beers, clear differences were observed between alcoholic and non-alcoholic beers, as well as those beers with high or low mouthfeel rating. Text-mining and clustering of the written reviews led to the development of 7 overall sensory descriptors; "watery", "smooth", "thick", "bitter", "foam", "astringent", and "sour", related to mouthfeel. Frictional parameters related to the static (speed range ~10-8-10-5 m/s), boundary (speed range ~10¬-5-5*10-5 m/s) and beginning of the mixed regime (speed range ~5*10-5-10-4 m/s) were correlated with "watery", "smooth", and "thick", while "bitter", "foam", "astringent", and "sour" were represented later in the mixed regime (speed range ~10-4-10-3 m/s). These results are significant in two ways; firstly, they indicate the usefulness of online beer reviews as a means to gather reliable sensory data, and secondly, they demonstrate tribology as a tool to instrumentally define and determine important mouthfeel parameters of beer. Further research is needed to fully validate this methodology; results from the online database should be compared to the outcome of a consumer panel under controlled settings, and a wider range of beers of different styles should be tested to fully understand the correlations between sensory phenomena and frictional parameters.

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